The GearWrench Locking Impact Extensions are made from impact grade chrome molybdenum alloy steel (Cr-Mo), have a manganese phosphate coating that provides corrosion resistance and feature a pull collar locking mechanism. The Long Locking Impact Extensions line is available in 3/8” and 1/2” drives. The 3/8” Drive Long Locking Impact Extension come in 18” (No. 84436N), 24” (No. 84437N) and 33” (No. 84438N). The 1/2” Drive Long Locking Impact Extension comes in 18” (No. 84651N), 24” (No. 84652N) and 31” (No. 84653N).